IntroductionPregnancy's physiological changes and weight gain can decrease balance control, increasing the risk of falls and impacting quality of life. The effect of obesity on balance control in pregnant women needs further investigation. ObjectiveInvestigate the effect of obesity during pregnancy on center of pressure (COP) control under sensory disturbances at different gestational age. MethodsThe COP (95% ellipse area, mean velocity and total length) of 23 pregnant women classified as normal weight (CG: n = 12) and obese (OG: n = 11) was evaluated at three gestational-age week times (T1 = 16th, T2 = 24th, T3 = 32nd week) on a force platform on standing position (SP) and under three disturbances: 1) visual disturbance (eyes closed), 2) proprioceptive disturbance (over an unstable surface) and, 3) vestibular disturbance (head movement). A mixed ANOVA (3 repeated measures vs. 2 groups) and LSD post-hoc was applied to examine main effects and interactions. Effect sizes were assessed using generalized eta squared (η2). ResultsAs main effect, in SP, COP area increased from T2 to T3 for both groups (P = 0.021, η2 = 0.193). One interaction was observed, under visual disturbance, the area increased from T2 to T3 only in the CG group (P = 0.020, η2 = 0.195). ConclusionThe progression of pregnancy negatively impacts postural stability throughout its course. Visual disturbance only affected the balance of the CG. Hence, obesity combined with pregnancy does not appear to alter COP variables.